Many homes and businesses receive Internet data from the Internet via a cable network, a telephone network, or a wireless network. These dwellings may also receive television data from a television network, such as a cable television network, a broadcast television network, an Internet Protocol Television (IPTV) network, or a satellite network. The dwellings may also receive telephone data from a telephone network or from the Internet. Alternatively, the dwellings may receive television data, telephone data, and Internet data from a single service provider. In some systems, the television data, the telephone data, and the Internet data may be provided by a fiber optic cable that feeds existing telephone lines that are wired into the dwellings. For example, a supplier of television, telephone, and Internet data may provide a broadband signal carrying the data into a neighborhood of dwellings. Within a dwelling, the broadband signal can be routed to a television, a telephone, a computer, or other device. In some households, a modem, a residential gateway, a set top box, or other customer premises equipment (CPE) may receive the broadband signal and route the television data, the telephone data, and the Internet data to one or more devices. The television data is typically routed to a television. The telephone data is typically routed to a telephone. The Internet data is typically routed to a computer.
Increasingly, many subscribers use more than one data service on a device. For example, a television may display content from a television network and from the Internet. A telephone may receive audio data from a telephone network and Internet data from the Internet or television data from a telephone network. A computer may receive and display content from the Internet and from a television network. When more than one data service is used by a subscriber device, there is an increased risk that a fault in one data service can disrupt the rendering of data of another data service. For example, when a television renders both television data and Internet data, there is a risk that a virus in the Internet data may cause a fault in the operation of a set top box to which the television data and the Internet data are routed. A fault in the operation of the set top box may, in turn, cause a fault in the rendering of the television data.